Cable backplane system

ABSTRACT

A cable backplane system includes a backplane having a plurality of openings therethrough and a cable rack coupled to a rear of the backplane. The cable rack includes a tray having a frame surrounding a raceway and a brick held by the tray. The brick has side spacers at opposite sides of the brick and plates coupled to the side spacers that support a plurality of cable connector assemblies. Each cable connector assembly is positioned between and supported by corresponding plates on opposite sides of the cable connectors with the cable connectors positioned in corresponding openings in the backplane. The plates each include a hem folded over at a rear of the plate. The hem has an edge positioned rearward of the cable connectors and supporting the cable connectors from retreating from the openings in the backplane.

BACKGROUND OF THE INVENTION

The subject matter herein relates generally to a cable backplane system.

Communication systems, such as network systems, servers, data centers,and the like, use large printed circuit boards, known as backplanes, tointerconnect midplanes, daughtercards, line cards and/or switch cards.The communication systems use high speed differential connectors mountedto the backplane and high speed differential connectors mounted to theline cards and switch cards to transmit signals therebetween. Thebackplane interconnects the various connectors using traces along thecircuit board.

As the density of the systems increase and requirements for high speedlines increase, the printed circuit boards continue to become larger andthe signal integrity inherently degrades as the signals travel furtheralong the entire channel. At least some systems have replaced thetraditional backplanes with cable assemblies. However, packaging oflarge numbers of cable assemblies is difficult. Cable management is alimiting factor in such systems. Additionally, assembly of such systemswith the large number of cables is problematic. Holding the cableconnectors in proper position for mating with the line and switch cardsis difficult.

A need remains for a cable backplane system that may be assembled in acost effective and reliable manner.

BRIEF DESCRIPTION OF THE INVENTION

In one embodiment, a cable backplane system is provided including abackplane having a plurality of openings therethrough and a cable rackcoupled to a rear of the backplane. The cable rack includes a trayhaving a frame surrounding a raceway and a brick held by the tray. Thebrick has side spacers at opposite sides of the brick. The brick hasplates coupled to the side spacers that support a plurality of cableconnector assemblies. Each cable connector assembly has a plurality ofcables extending between at least two cable connectors. The cables arerouted in the raceway. Each cable connector assembly is positionedbetween and supported by corresponding plates on opposite sides of thecable connectors with the cable connectors positioned in correspondingopenings in the backplane. The plates each include a hem folded over ata rear of the plate. The hem has an edge positioned rearward of thecable connectors and supporting the cable connectors from retreatingfrom the openings in the backplane.

Optionally, the hem may extend along an interior surface of the plate ata rear of the plate. The hem may be fixed to the plate. The hem maydouble a thickness of the plate to stiffen the plate. Optionally, theplate may be folded over at a rear of the plate to form the hem. Theplate may have a curved edge at the rear.

Optionally, the edge of the hem may be forward facing. The edge mayblock the cable connectors from moving in a rearward direction.Optionally, the cable connectors may each include a housing and aplurality of contact modules received in the housing. The cables mayextend reward from the contact modules. The edge of the hem may blockremoval of the contact modules from the housing.

Optionally, the plates may include slots therein. The cable connectorsmay have lugs received in the slots to hold the cable connectors in theplates. The slots may be oversized relative to the lugs to allow thecable connectors to float relative to the plates. The cable connectorsmay float in at least two directions relative to the plates. The spacersmay be coupled to the plates using float mechanisms that allow limitedmovement of the plates relative to the spacers.

In another embodiment, a cable rack for a cable backplane system isprovided that includes a tray having a frame with side walls surroundinga raceway. A brick is held by the tray. The brick has side spacers atopposite sides of the brick. The brick has plates coupled to the sidespacers. Each plate has slots formed therein proximate to a front of theplate. The plates support a plurality of cable connector assemblies.Each cable connector assembly has a plurality of cables extendingbetween at least two cable connectors. The cables are routed in theraceway. Each cable connector has lugs extending therefrom that arereceived in corresponding slots in the plates. The slots are oversizedrelative to the lugs to allow the cable connectors to float relative tothe plates. Optionally, the plates each include a hem folded over at arear of the plate, the hem having an edge positioned rearward of thecable connectors and blocking the cable connectors from moving rearwardrelative to the plates.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front perspective view of a cable backplane system formed inaccordance with an exemplary embodiment.

FIG. 2 is a rear perspective view of the cable backplane system.

FIG. 3 illustrates a backplane of the cable backplane system and formedin accordance with an exemplary embodiment.

FIG. 4 illustrates a cable connector assembly of the cable backplanesystem and formed in accordance with an exemplary embodiment.

FIG. 5 illustrates a cable connector assembly formed in accordance withan exemplary embodiment.

FIG. 6 illustrates a cable rack of the cable backplane system and formedin accordance with an exemplary embodiment.

FIG. 7 is a front view of a portion of the cable backplane system.

FIG. 8 is a front view of a portion of the cable backplane system.

FIG. 9 is a perspective view of a plate of the cable backplane system.

FIG. 10 illustrates a portion of the cable backplane system showingcable connectors mounted between plates.

FIG. 11 illustrates a portion of the cable backplane system showing aswitch card and corresponding card connectors being mated to the cablebackplane system.

FIG. 12 is a front view of a cable backplane system formed in accordancewith an exemplary embodiment.

FIG. 13 is a rear perspective view of the cable backplane system.

FIG. 14 is a front view of a portion of the cable backplane system.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 is a front perspective view of a cable backplane system 100formed in accordance with an exemplary embodiment. FIG. 2 is a rearperspective view of the cable backplane system 100. The cable backplanesystem 100 is used in a data communication application, such as anetwork switch. The cable backplane system 100 interconnects line cards102 and switch cards 104 using cable connector assemblies 106. The cablebackplane system 100 may be used to interconnect with other types ofconnectors and/or cards, such as daughtercards, in other embodiments.

The cable connector assemblies 106 include cable connectors 116 that areinterconnected by cables within the cable backplane system 100. Thecable connector assemblies 106 eliminate interconnections via traces ofa circuit board, such as a backplane circuit board. The cable connectorassemblies 106 have improved signal performance along the signal pathsbetween various connectors of the cable backplane system 100 as comparedto conventional backplanes. The cable connector assemblies 106 supporthigher speeds, longer signal path lengths and lower cost per channel ascompared to conventional backplanes. The cable connector assemblies 106provide shielding of signal lines for improved signal performance. Thecable connector assemblies 106 are packaged in a structure that allowsaccurate cable and connector location for mating with the correspondingline cards 102 and switch cards 104.

The cable backplane system 100 includes a chassis 110 that supports thecomponents of the cable backplane system 100. The chassis 110 mayinclude a rack, a cabinet or other suitable structures for holding thecomponents of the cable backplane system 100. The chassis 110 mayinclude structures for guiding, supporting and/or securing the linescards 102 and switch cards 104 coupled to the cable backplane system100.

The cable backplane system 100 includes a cable rack 112 that supportsand/or manages the cables of the cable connector assemblies 106. Thecable rack 112 includes a plurality of trays 114 that are held togetherand extend along different portions of the cable backplane system 100.The trays 114 may be box-shaped and define raceways for the cables. Thecable rack 112 supports a plurality of the cable connectors 116 whichform parts of the cable connector assemblies 106.

The cable backplane system 100 includes a backplane 120. The backplane120 may be a circuit board and may be manufactured from typical circuitboard material, such as FR-4 material. Electrical components, such aspower supplies, fans, connectors, and the like may be attached to thebackplane 120. Such electrical components may be electrically connectedto traces of the backplane 120.

The backplane 120 and cable rack 112, with the cable connectorassemblies 106, are coupled together to form the cable backplane system100. The cable rack 112 is provided along a rear 124 of the backplane120. The cable connectors 116 extend through openings 126 in thebackplane 120 and are presented at a front 128 of the backplane 120 formating with the line and switch cards 102, 104. The cable connectors 116are not electrically connected to the backplane 120, as is typical ofconventional backplanes, but rather the cable connectors 116 areinterconnected by cables extending between the cable connectors 116.

In an exemplary embodiment, the cable rack 112 is flexible to allow thecable connectors 116 to align with and pass through the openings 126.Optionally, portions of the trays 114 may pass through the openings 126with the cable connectors 116. The trays 114 may float relative to eachother to properly align the cable connectors 116 with the correspondingopenings 126. The backplane 120 holds the cable connectors 116 inprecise locations for mating with the line and switch cards 102, 104.The backplane 120 has tight tolerances to control mating with the lineand switch cards 102, 104. The cable rack 112 is flexible to allow thetrays 114 to be properly aligned relative to the backplane 120. In anexemplary embodiment, the cable connectors 116 float relative to oneanother and relative to the trays 114 to allow precise positioning ofthe cable connectors 116 relative to the backplane 120 for mating withthe line and switch cards 102, 104. The line and switch cards 102, 104have card connectors 132, 134, respectively, that mate withcorresponding cable connectors 116. The cable connectors 116 need to beprecisely positioned relative to the backplane 120 for mating withcorresponding card connectors 132, 134.

FIG. 3 illustrates the backplane 120 formed in accordance with anexemplary embodiment. The backplane 120 includes the openings 126 thatreceive the cable connectors 116 and/or portions of the trays 114 (bothshown in FIG. 1). The openings 126 may be single openings that receivesingle cable connectors 116, such as the cable connectors 116 associatedwith the line cards 102 (shown in FIG. 1). The openings 126 may be largeopenings that receive multiple cable connectors 116, such as the cableconnectors associated with the switch cards 104 (shown in FIG. 1).

The backplane 120 includes crossbars 140 between adjacent openings 126.The crossbars 140 provide support for the backplane 120. The crossbars140 provide a mounting location for mounting blocks 142 (examples ofwhich are shown mounted to the backplane 120 for reference) used tosecure the cable connectors 116 to the backplane 120. Optionally,mounting blocks 142 may be provided at each crossbar 140. Mountingblocks 142 may be provided adjacent each opening 126. The crossbars 140may define stiffeners for the mounting blocks 142 during assembly of thecable backplane system 100 (shown in FIG. 1). The mounting blocks 142may be metal stiffeners separately fabricated from the backplane 120 andattached to the backplane 120. Alternatively, the mounting blocks 142may be part of the backplane 120. For example, the mounting blocks 142may be defined by an opening through the backplane 120 and the area ofthe backplane 120 around such opening. The opening may be threaded. Thebackplane 120 may be thicker in the area of the mounting block 142 toadd rigidity to the backplane 120 in such area.

The backplane 120 includes holes 144 therethrough that receive guidefeatures, fasteners or other components used to assembly the cablebackplane system 100. The backplane 120 may include component openings146 therethrough that receive other electrical components that areattached to the backplane 120. Some electrical components may be surfacemounted to the backplane 120.

FIG. 4 illustrates a cable connector assembly 106 formed in accordancewith an exemplary embodiment. The cable connector assembly 106 includesa plurality of the cable connectors 116, which may be referred tohereinafter as first and second cable connectors 116′, 116″, and a cablebundle 150 between the cable connectors 116. The cable connectors 116are provided at ends of the cable bundle 150. The cable bundle 150includes a plurality of cables 152. Optionally, the first cableconnector 116′ may be connected to a card connector 132 (shown inFIG. 1) of a line card 102 (shown in FIG. 1) and the second cableconnector 116″ may be connected to a card connector 134 (shown inFIG. 1) of the switch card 104 (shown in FIG. 1).

Optionally, the cable connectors 116 may be identical to one another.The cable connectors 116 may define header connectors. The cableconnectors 116 are configured to be mated with corresponding cardconnectors 132, 134, which may be receptacle connectors, such as STRADAWhisper receptacle connectors, commercially available from TEConnectivity, Harrisburg, Pa. In an exemplary embodiment, the cableconnector 116 is a high speed differential pair cable connector thatincludes a plurality of differential pairs of conductors mated at acommon mating interface. The differential conductors are shielded alongthe signal paths thereof to reduce noise, crosstalk and otherinterference along the signal paths of the differential pairs.

In an exemplary embodiment, the cables 152 are twin axial cables havingtwo signal wires within a common jacket of the cable 152. The signalwires convey differential signals. In an exemplary embodiment, thesignal wires are shielded, such as with a cable braid of the cable 152.Optionally, each of the signal wires may be individually shielded. Othertypes of cables 152 may be provided in alternative embodiments. Forexample, coaxial cables may extend from the cable connector 116 eachcarrying a single signal conductor therein.

The cable connector 116 includes a header housing 160 holding aplurality of contact modules 162. The header housing 160 includes a basewall 164 and shroud walls 166 extending from the base wall 164 to definea mating cavity 168 configured to receive the corresponding cardconnector 132, 134. The shroud walls 166 guide mating of the cardconnector 132, 134 with the cable connector 116. In an exemplaryembodiment, the header housing 160 has lugs 170 extending outward fromthe walls 166. The lugs 170 are used to locate the cable connector 116with respect to the corresponding tray 114 (shown in FIG. 2).

Each of the contact modules 162 includes a plurality of cable assemblies180 held by a support body 182. Each cable assembly 180 includes a pairof signal contacts 186 terminated to corresponding signals wires of thecable 152. Each cable assembly 180 also includes a ground shield 188providing shielding for the signal contacts 186. In an exemplaryembodiment, the ground shield 188 peripherally surrounds the signalcontacts 186 along the entire length of the signal contacts 186 toensure that the signal paths are electrically shielded frominterference.

The support body 182 provides support for the cable assemblies 180. Thecables 152 extend into the support body 182 such that the support body182 supports a portion of the cables 152. The support body 182 mayprovide strain relief for the cables 152. Optionally, the support body182 may be manufactured from a plastic material. Alternatively, thesupport body 182 may be manufactured from a metal material. The supportbody 182 may be a metalized plastic material to provide additionalshielding for the cables 152 and the cable assemblies 180. Optionally,the support body 182 may include a metal plate electrically connected toeach ground shield to electrically common each ground shield 188 and adielectric overmold overmolded around the cables 106 and portions of themetal plate to support the cables 152 and cable assemblies 180.

Multiple contact modules 162 are loaded into the header housing 160. Theheader housing 160 holds the contact modules 162 in parallel such thatthe cable assemblies 180 are aligned in a column. Any number of contactmodules 162 may be held by the header housing 160 depending on theparticular application. When the contact modules 162 are stacked in theheader housing 160, the cable assemblies 180 may also be aligned inrows.

FIG. 5 illustrates a cable connector assembly 190 formed in accordancewith an exemplary embodiment. The cable connector assembly 190 issimilar to the cable connector assembly 106 (shown in FIG. 4); howeverthe cable connector assembly 190 includes more cable connectors 192(e.g. four cable connectors 192 are shown in the embodiment illustratedin FIG. 5). Some of the cable connectors 192 may be used to interconnectwith receptacle or card connectors 134 associated with the switch card104 (both shown in FIG. 1), such as the bottom two cable connectors 192,while other cable connectors 192 may be used to interconnect withreceptacle or card connectors 132 associated with the line card 102(both shown in FIG. 1). Optionally, cables 194 from the same cableconnector 192, such as cables from different contact modules 196, may berouted to several other cable connectors 192.

FIG. 6 illustrates the cable rack 112. The cable rack 112 includes oneor more trays 114 connected together to form the cable rack 112. In theillustrated embodiment, the cable rack 112 includes five trays 114 a,114 b, 114 c, 114 d and 114 e; however any number of trays 114 may beused in alternative embodiments. The trays 114 are coupled together intoan H-shaped configuration having the first tray 114 a at a centrallocation with the other trays 114 b, 114 c, 114 d, 114 e extendingoutward from the first tray 114 a as legs. The cable rack 112 may haveother shapes in alternative embodiments.

In an exemplary embodiment, the first tray 114 a is used to hold thecable connectors 116 that are mated with the card connectors 134 of theswitch cards 104 (both shown in FIG. 1). The cable connectors 116 in thefirst tray 114 a may be held together as a brick 228. The cableconnectors 116 of each brick 228 are connected to the card connectors134 of the same switch card 104. The other trays 114 b, 114 c, 114 d,114 e are used to hold the cable connectors 116 that are mated with thecard connectors 132 of the line cards 102 (both shown in FIG. 1).Optionally, the cable connectors 116 aligned at the same verticalposition but in different trays (e.g. 114 b and 114 d or 114 c and 114e) are connected to the card connectors 132 of the same line card 102.

Each tray 114 includes a frame 200 surrounding a raceway through whichthe cables 152 (shown in FIG. 4) are routed. The raceways are open toone another to allow the cables 152 to be routed from one tray 114 intoanother tray 114. The frame 200 includes side walls 202 extendingbetween a front edge 204 and a rear 206 of the tray 114. A back wall 208covers the raceway at the rear 206. The frame 200 is open at the frontedge 204 between the side walls 202 to receive the cable connectors 116therein.

In an exemplary embodiment, the side walls 202 and back wall 208 aresheet metal pieces that are stamped, formed and coupled together, suchas using fasteners or other connecting means. The sheet metal may bethin enough to allow the frame 200 to have some flexibility for moving,twisting or otherwise manipulating the trays 114 into position relativeto the backplane 120 (shown in FIG. 3) to position the cable connectors116 in the openings 126 (shown in FIG. 3) in the backplane 120.Optionally, the trays 114 may be connected to each other with somefreedom of movement or float built in to the connection to allow thetrays 114 to move relative to one another to properly align the cableconnectors 116 with the openings 126 in the backplane 120.

In an exemplary embodiment, the cable rack 112 includes handles 210 usedto hold the trays 114 together. The handles 210 may be used to pick upthe cable rack 112 and load the cable rack 112 onto the backplane 120during assembly. Because of the size of the cable rack 112, assembly andloading of the cable connectors 116 and/or front edge 204 of the frame200 into the openings 126 may be difficult. The handles 210 make movingof the cable rack 112 easier. The handles 210 may be removable once thecable rack 112 is coupled to the backplane 120.

The cable rack 112 includes a plurality of spacers 220, 222, 224, 226used to hold positions of the cable connectors 116. The spacers 220,222, 224, 226 may be different types of spacers. The spacers 220, 222,224, 226 may have different sizes, shapes and/or features, such as guidepins. The spacers 220, 222, 224, 226 generally have similar functions,such as supporting one or more cable connectors 116.

In the illustrated embodiment, the spacers 220 are provided along sidesof corresponding bricks 228 of cable connectors 116 that are located inthe tray 114 a. The bricks 228 are a group of cable connectors 116 thatare held together in a stacked arrangement for mating with a pluralityof the card connectors 134 of the same switch card 104 (both shown inFIG. 1). The spacers 220 may be referred to hereinafter as side spacers220 or brick spacers 220. The spacers 222 are provided at ends of thetrays 114 b, 114 c, 114 d, 114 e, such as to support the end-most cableconnectors 116 in such trays 114. The spacers 222 may be referred tohereinafter as end spacers 222. The end spacers 222 are provided at thetop and bottom ends of the cable rack 112. The end spacers 222 support asingle cable connector 116. The spacers 224 are provided betweenadjacent cable connectors 116. The spacers 224 may be referred tohereinafter as intermediate spacers 224. The spacers 224 each supporttwo cable connectors 116. The spacers 226 are provided between adjacentcable connectors 116, similar to the intermediate spacers 224; howeverthe spacers 226 have guide pins extending therefrom, which may be usedfor guiding the cable rack 112 into alignment and engagement with thebackplane 120. The spacers 226 may be referred to hereinafter as guidespacers 226.

In an exemplary embodiment, the cable connectors 116 are movablerelative to the spacers 220, 222, 224, 226 to allow the cable connectors116 to align with the corresponding openings 126 during assembly of thecable rack 112 and backplane 120. For example, the spacers 220, 222,224, 226 may allow X, Y and/or Z float to allow fine alignment of thecable connectors 116 with the openings 126. Once the cable connectors116 are positioned in the openings 126, the spacers 220, 222, 224, 226may be fixed to the mounting blocks 142 (shown in FIG. 3), such as usingfasteners to securely couple the cable rack 112 to the backplane 120with the cable connectors 116 generally in position for mating with thecorresponding card connectors 132, 134. In an exemplary embodiment, thecable connectors 116 are configured to float within the openings 126relative to the spacers 220, 222, 224, 226 to obtain a true position foraligning to and mating with the corresponding card connectors 132, 134.

FIG. 7 illustrates one of the bricks 228 forming part of the first tray114 a (shown in FIG. 6). The brick 228 includes plates 402, which may betop and bottom plates extending along tops and bottoms of the cableconnectors 116. The plates hold the cable connectors 116 of the brick228. The plates 402 may form parts of the side walls 202 (shown in FIG.6) of the tray 114 a.

The side spacers 220 are positioned between the plates 402. The sidespacers 220 are configured to be coupled to corresponding mountingblocks 142 (shown in FIG. 3) on the backplane 120 (shown in FIG. 3). Themounting blocks 142 secure the side spacers 220 in place relative to thebackplane 120. The side spacers 220 are coupled to the plates 402 usingfloat mechanisms 400 which allow movement in mutually perpendicular X, Yand/or Z directions. The plates 402 and the cable connectors 116 arethus movable relative to the side spacers 220 to properly position thecable connectors 116 relative to the backplane 120.

FIG. 8 is a front view of a portion of the cable backplane system 100.FIG. 8 illustrates the trays 114 a, 114 b showing the spacers 220, 224,226 used for mounting the trays 114 to the backplane 120 (shown in FIG.1). In an exemplary embodiment, the first tray 114 a is secured to thesecond tray 114 b using float mechanisms 400. The float mechanisms 400are coupled to the side spacers 220. The side walls 202 of the firsttray 114 a are movable relative to the side spacer 220 usingcorresponding float mechanisms 400. The second tray 114 b is movablerelative to the side spacer 220 using corresponding float mechanisms400. The float mechanisms 400 thus allow relative movement between thefirst and second trays 114 a, 114 b. The float mechanisms 400 allowmovement in mutually perpendicular X, Y and Z directions. The othertrays 114 may be connected together in a similar manner using similartypes of float mechanisms 400.

In an exemplary embodiment, the float mechanisms 400 are fasteners suchas a countersink screws. The float mechanisms 400 may be fasteners thatare received in oversized holes or apertures in the trays 114 that allowthe float mechanisms 400 to move in one or more directions relative tothe trays 114. A circumferential gap may be defined around the floatmechanism 400 in the aperture in the side wall 202 allowing the floatmechanism 400 to move within the aperture. The size of the gap definesthe amount of float. Optionally, the gap may allow approximately 1.0 mmof float in the X, Y and Z directions; however the gap may allow more orless float in alternative embodiments. Other types of float mechanismsmay be used in alternative embodiments that tie the trays 114 togetherbut allow limited relative movement therebetween.

FIG. 9 is a perspective view of one of the plates 402. The plate 402includes a main panel 410 and a hem 412 folded along an interior surface414 of the main panel 410. The plate 402 is folded over to form the hem412. The main panel 410 includes a front 416 and a rear 418 opposite thefront 416. The hem 412 is provided at the rear 418. Optionally, the hem412 may be fixed to the main panel 410, such as by welding the hem 412to the main panel 410. The hem 412 doubles the thickness of the plate402 at the rear 418 to stiffen the plate 402. The hem 412 reducestwisting or bending of the plate 402, such as in the Y direction. In anexemplary embodiment, when the plate 402 is folded over to form the hem412, the plate 402 has a curved edge at the rear 418. The curved edgereduces the risk of cutting or slicing the cables 152 (shown in FIG. 4)that are routed into and out of the brick 228 (shown in FIG. 8). In anexemplary embodiment, the hem 412 has a forward facing edge 420. Asdescribed in further detail below, the forward facing edge 420 is usedto support the cable connectors 116 (shown in FIG. 8) relative to theplate 402.

The plate 402 has opposite first and second ends 422, 424 and oppositefirst and second sides 426, 428. The ends 422, 424 may define top andbottom ends. The sides 426, 428 are configured to engage the sidespacers 220 (shown in FIG. 8). The plate 402 includes a plurality ofslots 430 extending therethrough. The slots 430 may extend onlypartially therethrough, defining pockets.

Returning to FIG. 7, the slots 430 are configured to receive the lugs170 to support the housings 160 of the cable connectors 116. In anexemplary embodiment, the slots 430 are oversized relative to the lugs170 to allow the cable connectors 116 to float relative to the plate402. The size of the slots 430 relative to the lugs 170 defines theamount of float. The slots 430 may be oversized in at least two mutuallyperpendicular directions, such as the X and Z directions, to allow floatin at least two mutually perpendicular directions. Allowing the cableconnectors 116 to float allows the cable connectors 116 to align withthe card connectors 134 even after the tray 114 is secured to thebackplane 120. The cable connectors 116 can float within the opening 126in the backplane 120 to allow for proper mating with the card connectors134.

FIG. 10 illustrates a portion of the cable backplane system 100 showingthe cable connectors 116 mounted between the plates 402 of a brick 228.The hems 412 of both plates 402 are folded inward into the interior ofthe brick 228. The forward facing edges 420 of the hems 412 aregenerally aligned with one another and are positioned rearward of thecable connectors 116. The hems 412 are positioned directly behind thecontact modules 162 of the cable connectors 116. The hems 412 blockrearward movement of the contact modules 162 and thus prevent removal ofthe contact modules 162 from the housing 160. For example, when thecables 152 (shown in FIG. 4) are manipulated or pulled, the hems 412will prevent the contact modules 162 from being pulled out of thehousing 160. The hems 412 provide a backup retention feature in a Zdirection.

FIG. 11 illustrates a portion of the cable backplane system 100 showingthe switch card 104 and corresponding card connectors 134 being mated tothe brick 228. When the switch card 104 is plugged into the cablebackplane system 100, a plugging force 450 acts on the cable connectors116 in the Z direction. The plugging force 450 tends to push the cableconnectors 116 rearward. The hems 412 block the cable connectors 116from being pushed rearward and operate as a backup retention feature.When the switch card 104 is plugged into the cable backplane system 100,the plugging force 450 tends to force the plates 402 outward in the Ydirection. The hems 412 provide stiffening of the plates 402 to resistoutward deflection of the plates 402. If the plates 402 were allowed todeflect outward, the lugs 170 (shown in FIG. 7) might dislodge from theslots 430, allowing the cable connectors 116 to be forced out of thebrick 228.

FIG. 12 is a front view of a cable backplane system 300 formed inaccordance with an exemplary embodiment. FIG. 13 is a rear perspectiveview of the cable backplane system 300. The cable backplane system 300is similar to the cable backplane system 100 (shown in FIGS. 1 and 2)and includes similar components in a different arrangement than thearrangement of the cable backplane system 100. The cable backplanesystem 300 interconnects line cards 302 and switch cards 304 using cableconnector assemblies 306.

The cable backplane system 300 includes a chassis 310 that supports thecomponents of the cable backplane system 300. The chassis 310 mayinclude a rack, a cabinet or other suitable structures for holding thecomponents of the cable backplane system 300. The cable backplane system300 includes a cable rack 312 that supports and/or manages the cables ofthe cable backplane system 300. The cable rack 312 includes a pluralityof trays 314 that are held together and extend along different portionsof the cable backplane system 300. The trays 314 are arranged in adifferent arrangement than the arrangement of the trays 114 (shown inFIG. 2). The cable rack 312 supports a plurality of cable connectors316, which form parts of the cable connector assemblies 306. At leastsome of the cable connectors 316 may be arranged in bricks 318, similarto the bricks 228 (shown in FIG. 7). The bricks 318 may include similarcomponents as the bricks 228, such as plates having hems used to retainthe cable connectors 316 and slots that allow the cable connectors 316to float relative to the plates.

The cable backplane system 300 includes a plurality of backplanes 320.The backplanes 320 are separately manufactured from one another andseparately mounted to and supported by the chassis 310. In theillustrated embodiment, three backplanes 320 are separately mounted tothe chassis 310. The trays 314 interconnect with multiple backplanes320. In order for the trays 314 to connect to different backplanes 320,the trays 314 are movable relative to each other and/or the backplanes320. The trays 314 are flexible and have mounting features that allowthe trays 314 to float relative to each other. In an exemplaryembodiment, the mounting features are float mechanisms directly coupledbetween two trays 314 that allow the trays 314 to float and moverelative to one another in X, Y and Z directions.

In an exemplary embodiment, the cable rack 312 is flexible to allow thecable connectors 316 to align with and pass through openings 326 in thebackplanes 320. The trays 314 may float relative to each other toproperly align the cable connectors 316 with the corresponding openings326. The backplane 320 holds the cable connectors 316 in preciselocations for mating with the line and switch cards 302, 304.

In the illustrated embodiment, the cable rack 312 includes eight trays314 a, 314 b, 314 c, 314 d, 314 e, 314 f, 314 g and 314 h; however anynumber of trays 314 may be used in alternative embodiments. The trays314 are coupled together into an H-shaped configuration having four ofthe trays 314 a, 314 b, 314 c, 314 d at a central location with theother trays 314 e, 314 f, 314 g, 314 h extending above or belowcorresponding trays 314 a, 314 b, 314 c, 314 d as legs. The bottom trays314 e, 314 g are arranged in line with the corresponding center trays314 a, 314 c. The top trays 314 f, 314 h are offset from thecorresponding center trays 314 b, 314 d. The center trays 314 b, 314 dhave transition sections 328 that transition to the top trays 314 f, 314h. The top trays 314 f, 314 h are generally vertically aligned with thebottom trays 314 e, 314 g. The cable rack 312 may have other shapes inalternative embodiments.

In an exemplary embodiment, the center trays 314 a, 314 b, 314 c, 314 dare used to hold the cable connectors 316 that are mated with the cardconnectors of the switch cards 304 (shown in FIG. 12). The top andbottom trays 314 e, 314 f, 314 g, 314 h are used to hold the cableconnectors 316 that are mated with the card connectors of the line cards302 (shown in FIG. 12).

FIG. 14 is a front view of a portion of the cable backplane system 300.FIG. 14 illustrates two backplanes 320′, 320″ mounted to the chassis 310(shown in FIG. 12). FIG. 14 illustrate the trays 314 b, 314 f mounted tothe backplanes 320 and secured to each other using float mechanisms 330.The float mechanisms 330 allow the trays 314 b, 314 f to float and moverelative to one another in X, Y and Z directions. The cable connectorassemblies 306 within the respective trays 314 b, 314 f may be alignedwith the openings 326 and the float mechanisms 330 allow the trays 314b, 314 to move relative to each other to align with the correspondingopenings 326. For example, because the tray 314 b is coupled to onebackplane 320″ while the tray 314 f is coupled to the other backplane320′, the trays 314 b, 314 f need to be able to move relative to eachother to allow proper alignment with the corresponding backplane 320.The float mechanisms 330 tie the trays 314 together but allow some floator movement in at least two directions. In an exemplary embodiment thefloat mechanisms 330 allow relative movement of the trays 314 in threedimensions (e.g. X, Y and Z float). The float mechanisms may be shoulderscrews or other types of fasteners that secure the trays 314 togetherwhile allowing some limited movement between the trays 314. The trays314 may have oversized openings that allow the float mechanisms to floatwithin the openings.

The trays 314 each include a frame 340 surrounding a raceway throughwhich cables of the cable connector assemblies 306 (shown in FIG. 12)are routed. The raceways of the trays 314 b, 314 f are open to oneanother to allow the cables to be routed from one tray 314 b into theother tray 314 f. The frame 340 includes side walls 342, which may besheet metal pieces that are stamped, formed and coupled together, suchas using fasteners or other connecting means. The sheet metal may bethin enough to allow the frame 340 to have some flexibility for moving,twisting or otherwise manipulating the trays 314 into position relativeto the backplanes 320 to position the cable connectors 316 in thecorresponding openings 326. Optionally, the trays 314 may be connectedto each other with some freedom of movement or float built in to theconnection to allow the trays 314 to move relative to one another toproperly align the cable connectors 316 with the openings 326 in thebackplanes 320.

In an exemplary embodiment, the cable backplane system 300 includesspacers (not shown), similar to the spacers 220, 222, 224 and/or 226(shown in FIG. 6), between and supporting corresponding cable connectors316. At least some of the spacers may include guide pins 350 extendingforward therefrom. The guide pins 350 are loaded into correspondingholes 351 in the backplanes 320 to position the cable rack 312 relativeto the backplanes 320. The guide pins 350 may fix the X and Y positionof the spacer relative to the corresponding backplane 320, however thecable connectors may still be movable, such as to align with theopenings 326 and/or the card connectors of the line cards 302 and switchcards 304. The spacers may be secured to the trays 314 using floatmechanisms that allow the spacers to float with a limited range ofmotion relative to the trays 314. The spacers may thus be aligned withmounting blocks on the backplane 320 to position the cable connectorswith respect to the openings 326. The float mechanisms may be fastenersthat are received in oversized holes in the trays 314 that allow thefloat mechanisms to move in one or more directions relative to the trays314.

It is to be understood that the above description is intended to beillustrative, and not restrictive. For example, the above-describedembodiments (and/or aspects thereof) may be used in combination witheach other. In addition, many modifications may be made to adapt aparticular situation or material to the teachings of the inventionwithout departing from its scope. Dimensions, types of materials,orientations of the various components, and the number and positions ofthe various components described herein are intended to defineparameters of certain embodiments, and are by no means limiting and aremerely exemplary embodiments. Many other embodiments and modificationswithin the spirit and scope of the claims will be apparent to those ofskill in the art upon reviewing the above description. The scope of theinvention should, therefore, be determined with reference to theappended claims, along with the full scope of equivalents to which suchclaims are entitled. In the appended claims, the terms “including” and“in which” are used as the plain-English equivalents of the respectiveterms “comprising” and “wherein.” Moreover, in the following claims, theterms “first,” “second,” and “third,” etc. are used merely as labels,and are not intended to impose numerical requirements on their objects.Further, the limitations of the following claims are not written inmeans—plus-function format and are not intended to be interpreted basedon 35 U.S.C. §112, sixth paragraph, unless and until such claimlimitations expressly use the phrase “means for” followed by a statementof function void of further structure.

What is claimed is:
 1. A cable backplane system comprising: a backplanehaving a plurality of openings therethrough; a cable rack coupled to arear of the backplane, the cable rack comprising: a tray having a framesurrounding a raceway; a brick held by the tray, the brick having sidespacers at opposite sides of the brick, the brick having plates coupledto the side spacers, the plates supporting a plurality of cableconnector assemblies, each cable connector assembly having a pluralityof cables extending between at least two cable connectors, the cablesbeing routed in the raceway, each cable connector assembly positionedbetween and supported by corresponding plates on opposite sides of thecorresponding cable connectors with the cable connectors positioned incorresponding openings in the backplane; wherein the plates each includea hem folded over at a rear of the plate, the hem increasing a thicknessof the plate and providing rigidity to the plate along a length of theplate.
 2. The cable backplane system of claim 1, wherein the hem extendsalong an interior surface of the plate at the rear of the plate.
 3. Thecable backplane system of claim 1, wherein the hem is fixed to theplate.
 4. The cable backplane system of claim 1, wherein the hem doublesa thickness of the plate to stiffen the plate.
 5. The cable backplanesystem of claim 1, wherein the plate is folded over at the rear of theplate to form the hem, the plate having a curved edge at the rear. 6.The cable backplane system of claim 1, wherein the hem has an edgepositioned rearward of the cable connectors, the edge of the hem isforward facing, the edge blocking the cable connectors from moving in arearward direction.
 7. The cable backplane system of claim 1, whereinthe cable connectors each comprise a housing and a plurality of contactmodules received in the housing, the cables extending rearward from thecontact modules, the hem having an edge positioned rearward of the cableconnectors, the edge of the hem blocking removal of the contact modulesfrom the housing.
 8. The cable backplane system of claim 1, wherein theplates comprise slots therein, the cable connectors having lugs receivedin the slots to hold the cable connectors in the plates, the slots beingoversized relative to the lugs to allow the cable connectors to floatrelative to the plates.
 9. The cable backplane system of claim 8,wherein the cable connectors float in at least two mutuallyperpendicular directions relative to the plates.
 10. The cable backplanesystem of claim 1, wherein the side spacers are coupled to the platesusing float mechanisms, the float mechanism allowing limited movement ofthe plates relative to the side spacers.
 11. A cable rack for a cablebackplane system comprising: a tray having a frame with side wallssurrounding a raceway; a brick held by the tray, the brick having sidespacers at opposite sides of the brick, the brick having plates coupledto the side spacers, each plate having slots formed therein proximate toa front of the plate; wherein the plates support a plurality of cableconnector assemblies, each cable connector assembly having a pluralityof cables extending between at least two cable connectors, the cablesbeing routed in the raceway, each cable connector having lugs extendingtherefrom, the lugs of the cable connectors being received incorresponding slots in the plates, the slots being oversized relative tothe lugs to allow the cable connectors to float relative to the plates.12. The cable rack of claim 11, wherein the plates each include a hemfolded over at a rear of the plate, the hem having an edge positionedrearward of the cable connectors and blocking the cable connectors frommoving rearward relative to the plates.
 13. The cable rack of claim 12,wherein the hem extends along an interior surface of the plate at a rearof the plate.
 14. The cable rack of claim 12, wherein the hem is fixedto the plate.
 15. The cable rack of claim 12, wherein the hem doubles athickness of the plate to stiffen the plate.
 16. The cable rack of claim12, wherein the plate is folded over at a rear of the plate to form thehem, the plate having a curved edge at the rear.
 17. The cable rack ofclaim 12, wherein the edge of the hem is forward facing, the edgeblocking the cable connectors from moving in a rearward direction. 18.The cable rack of claim 12, wherein the cable connectors each comprise ahousing and a plurality of contact modules received in the housing, thecables extending rearward from the contact modules, the edge of the hemblocking removal of the contact modules from the housing.
 19. The cablerack of claim 11, wherein the cable connectors float in at least twomutually perpendicular directions relative to the plates.
 20. The cablerack of claim 11, wherein the side spacers are coupled to the platesusing float mechanisms, the float mechanism allowing limited movement ofthe plates relative to the side spacers.